Trends and outcomes in colorectal cancer surgery: a multicenter cross-sectional study of minimally invasive versus open techniques in Germany.

BACKGROUND: The objective of this study was to assess the trend from open to modern minimally invasive (laparoscopic and robot-assisted) surgical techniques for colorectal cancer (CRC) in Germany, with a particular focus on hospital mortality, postoperative complications, and length of hospital stay. METHODS: A multicenter cross-sectional study was conducted using data from 36 German hospitals, encompassing 1,250,029 cases from January 2019 to December 2023. The study included all hospitalized patients aged ≥ 18 with CRC who underwent surgery. Surgical cases were categorized as open or minimally invasive. Outcomes assessed included in-hospital mortality, morbidity, and hospital length of stay. Statistical analyses involved multivariable logistic and linear regression models adjusted for main diagnosis, metastasis presence, age, sex, and comorbidities. RESULTS: The study included 4525 CRC cases: 2767 underwent open surgery and 1758 underwent minimally invasive surgery (173 robotic). In-hospital mortality was significantly higher in open surgery (6.1% vs. 1.7%). Open surgery was also significantly associated with higher rates of acute post-hemorrhagic anemia (OR: 2.38; 95% CI: 1.87-3.02), respiratory failure (OR: 1.71; 95% CI: 1.34-2.18), and intraoperative and postprocedural complications (OR: 3.64; 95% CI: 2.83-4.70). Average hospital stay was longer for open surgery (19.5 days vs. 11.0 days). CONCLUSION: Despite the advantages of minimally invasive surgery, including reduced mortality, morbidity, and shorter hospital stays, open surgery remains the predominant approach for CRC in Germany. These findings underscore the need for increased adoption of minimally invasive techniques and highlight the potential benefits of shifting toward minimally invasive methods to enhance the overall quality of CRC care.

Elevated CO2, nutrition dilution, and shifts in Earth's insect abundance.

Declining insect populations are concerning, given the numerous ecosystem services provided by insects. Here, we examine yet another threat to global insect populations - nutrient dilution, the reduction in noncarbon essential nutrients in plant tissues. The rise of atmospheric CO2, and subsequent 'global greening', is a major driver of nutrient dilution. As plant nutrient concentrations are already low compared to animal tissues, further reductions can be detrimental to herbivore fitness, resulting in increased development times, smaller intraspecific body sizes, reduced reproduction, and reduced population sizes. By altering herbivore populations and traits, nutrient dilution can ramify up trophic levels. Conservation of Earth's biodiversity will require not just protection of habitat, but reductions in anthropogenic alterations to biogeochemical cycles, including the carbon cycle.

Nutrient dilution and the future of herbivore populations.

Nutrient dilution (ND) - the decrease in the concentration of nutritional elements in plant tissue - arises from an increase in the mass of carbohydrates and/or a decrease in the 20+ essential elements. Increasing CO2 levels and its promotion of biomass are linked to nutrient dilution. We build a case for nutrient dilution as a key driver in global declines in herbivore abundance. Herbivores must build element-rich animal tissue from nutrient-poor plant tissue, and their abundance commonly increases with fertilization of both macro- and micronutrients. We predict the global impacts of nutrient dilution will be magnified in some of Earth's most biodiverse, highly productive, and/or nutrient-poor ecosystems and should favor specific traits of herbivores, including sap-feeding and ruminant microbiomes.

Capacity and establishment rules govern the number of nonnative species in communities of ground-dwelling invertebrates.

Nonnative species are a key agent of global change. However, nonnative invertebrates remain understudied at the community scales where they are most likely to drive local extirpations. We use the North American NEON pitfall trapping network to document the number of nonnative species from 51 invertebrate communities, testing four classes of drivers. We sequenced samples using the eDNA from the sample's storage ethanol. We used AICc informed regression to evaluate how native species richness, productivity, habitat, temperature, and human population density and vehicular traffic account for continent-wide variation in the number of nonnative species in a local community. The percentage of nonnatives varied 3-fold among habitat types and over 10-fold (0%-14%) overall. We found evidence for two types of constraints on nonnative diversity. Consistent with Capacity rules (i.e., how the number of niches and individuals reflect the number of species an ecosystem can support) nonnatives increased with existing native species richness and ecosystem productivity. Consistent with Establishment Rules (i.e., how the dispersal rate of nonnative propagules and the number of open sites limits nonnative species richness) nonnatives increased with automobile traffic-a measure of human-generated propagule pressure-and were twice as common in pastures than native grasslands. After accounting for drivers associated with a community's ability to support native species (native species richness and productivity), nonnatives are more common in communities that are regularly seasonally disturbed (pastures and, potentially deciduous forests) and those experiencing more vehicular traffic. These baseline values across the US North America will allow NEON's monitoring mission to document how anthropogenic change-from disturbance to propagule transport, from temperature to trends in local extinction-further shape biotic homogenization.

Electrolytes on the prairie: How urine-like additions of Na and K shape the dynamics of a grassland food web.

The electrolytes Na and K both function to maintain water balance and membrane potential. However, these elements work differently in plants-where K is the primary electrolyte-than in animals-where ATPases require a balanced supply of Na and K. Here, we use monthly factorial additions of Na and K to simulate bovine urine inputs and explore how these electrolytes ramify through a prairie food web. Against a seasonal trend of increasing grass biomass and decreasing water and elemental tissue concentrations, +K and +Na plots boosted water content and, when added together, plant biomass. Compared to control plots, +Na and +K plots increased element concentrations in above-ground plant tissue early in summer and decreased them in September. Simultaneously, invertebrate abundance on Na and K additions were sequentially higher and lower than control plots from June to September and were most suppressed when grass was most nutrient rich. K was the more effective plant electrolyte, but Na frequently promoted similar changes in grass ionomes. The soluble/leachable ions of Na and K showed significant ability to shape plant growth, water content, and the 15-element ionome, with consequences for higher trophic levels. Grasslands with high inputs of Na and K-via large mammal grazers or coastal aerosol deposition-likely enhance the ability of plants to adjust their above-ground ionomes, with dramatic consequences for the distribution of invertebrate consumers.

Temperature-habitat interactions constrain seasonal activity in a continental array of pitfall traps.

Activity density (AD), the rate at which animals collectively move through their environment, emerges as the product of a taxon's local abundance and its velocity. We analyze drivers of seasonal AD using 47 localities from the National Ecological Observatory Network (NEON) both to better understand variation in ecosystem rates like pollination and seed dispersal as well as the constraints of using AD to monitor invertebrate populations. AD was measured as volume from biweekly pitfall trap arrays (ml trap-1 14 days-1 ). Pooled samples from 2017 to 2018 revealed AD extrema at most temperatures but with a strongly positive overall slope. However, habitat types varied widely in AD's seasonal temperature sensitivity, from negative in wetlands to positive in mixed forest, grassland, and shrub habitats. The temperature of maximum AD varied threefold across the 47 localities; it tracked the threefold geographic variation in maximum growing season temperature with a consistent gap of ca. 3°C across habitats, a novel macroecological result. AD holds potential as an effective proxy for investigating ecosystem rates driven by activity. However, our results suggest that its use for monitoring insect abundance is complicated by the many ways that both abundance and velocity are constrained by a locality's temperature and plant physiognomy.

Tropical ant community responses to experimental soil warming.

Climate change is one of the primary agents of the global decline in insect abundance. Because of their narrow thermal ranges, tropical ectotherms are predicted to be most threatened by global warming, yet tests of this prediction are often confounded by other anthropogenic disturbances. We used a tropical forest soil warming experiment to directly test the effect of temperature increase on litter-dwelling ants. Two years of continuous warming led to a change in ant community between warming and control plots. Specifically, six ant genera were recorded only on warming plots, and one genus only on control plots. Wasmannia auropuctata, a species often invasive elsewhere but native to this forest, was more abundant in warmed plots. Ant recruitment at baits was best predicted by soil surface temperature and ant heat tolerance. These results suggest that heat tolerance is useful for predicting changes in daily foraging activity, which is directly tied to colony fitness. We show that a 2-year increase in temperature (of 2-4°C) can have a profound effect on the most abundant insects, potentially favouring species with invasive traits and moderate heat tolerances.

Sodium-enriched floral nectar increases pollinator visitation rate and diversity.

Plants have evolved a variety of approaches to attract pollinators, including enriching their nectar with essential nutrients. Because sodium is an essential nutrient for pollinators, and sodium concentration in nectar can vary both within and among species, we explored whether experimentally enriching floral nectar with sodium in five plant species would influence pollinator visitation and diversity. We found that the number of visits by pollinators increased on plants with sodium-enriched nectar, regardless of plant species, relative to plants receiving control nectar. Similarly, the number of species visiting plants with sodium-enriched nectar was twice that of controls. Our findings suggest that sodium in floral nectar may play an important but unappreciated role in the ecology and evolution of plant-pollinator mutualisms.

How and why grasshopper community maturation rates are slowing on a North American tall grass prairie.

Invertebrate growth rates have been changing in the Anthropocene. We examine rates of seasonal maturation in a grasshopper community that has been declining annually greater than 2% a year over 34 years. As this grassland has experienced a 1°C increase in temperature, higher plant biomass and lower nutrient densities, the community is maturing more slowly. Community maturation had a nutritional component: declining in years/watersheds with lower plant nitrogen. The effects of fire frequency were consistent with effects of plant nitrogen. Principal components analysis also suggests associated changes in species composition-declines in the densities of grass feeders were associated with declines in community maturation rates. We conclude that slowed maturation rates-a trend counteracted by frequent burning-likely contribute to long-term decline of this dominant herbivore.

Activity density at a continental scale: What drives invertebrate biomass moving across the soil surface?

Activity density (AD), the rate that an individual taxon or its biomass moves through the environment, is used both to monitor communities and quantify the potential for ecosystem work. The Abundance Velocity Hypothesis posited that AD increases with aboveground net primary productivity (ANPP) and is a unimodal function of temperature. Here we show that, at continental extents, increasing ANPP may have nonlinear effects on AD: increasing abundance, but decreasing velocity as accumulating vegetation interferes with movement. We use 5 yr of data from the NEON invertebrate pitfall trap arrays including 43 locations and four habitat types for a total of 77 habitat-site combinations to evaluate continental drivers of invertebrate AD. ANPP and temperature accounted for one-third to 92% of variation in AD. As predicted, AD was a unimodal function of temperature in forests and grasslands but increased linearly in open scrublands. ANPP yielded further nonlinear effects, generating unimodal AD curves in wetlands, and bimodal curves in forests. While all four habitats showed no AD trends over 5 yr of sampling, these nonlinearities suggest that trends in AD, often used to infer changes in insect abundance, will vary qualitatively across ecoregions.